and the man who has been playing president obama in governor romney's mock debates, ohio senator rob portman said over the weekend the main change they made to their debate prep is that they are getting ready, charlie, for a more aggressive president obama. >> nancy cordes, thank you. frank luntz is a republican strategist and cbs news political analyst. good morning. aggressive. what does that mean and what risks are there for the president? >> if i am barack obama, i'm focusing on one number. 47%. and i'm trying to drive that home as much as i possibly can, particularly because it's a live studio audience and they are the ones asking the questions. which one of you think you fall in the 47% and governor romney who do you represent here and who do you not? and if i'm mitt romney i'm going to talk about in two words you deserve, you deserve to get your questions answered, mr. president you were asked a direct question and you chose to attack me. how will you work with congress when all you do is take. >> is this format easier for one or the other? >> it's easier and more difficult fo